Stent grafts have become a popular treatment option for aneurysms. Typically, a stent graft is delivered to a treatment site through endovascular insertion via an introducer or catheter. Subsequent radial expansion retains the graft in position relative to the vessel wall. In instances where an aneurysm is located along a length of vessel on which branch vessels are not present, a simple tubular cylindrical stent graft is suitable. Additionally, stent grafts are known to the art for treatment of aneurysms in aortic regions where the distal end of the graft bifurcates to define two lumens so as to extend into arterial branches. Such bifurcated stent grafts are well known for the treatment of ascending thoracic and abdominal aortic aneurysms. Exemplary stents of this kind are embodied in U.S. Pat. Nos. 6,695,875 B2 and 6,814,752 B1 and U.S. patent application Publication 2004/0230287 A1.
Currently, aneurysms in certain anatomic regions of the aorta have proved difficult to properly repair with a stent graft. In particular, treatment of suprarenal aortic aneurysms has proved problematic. In such locales, the lack of a neck above the aneurysm precludes attachment of a conventional endovascular graft. Additionally, in the treatment of an aneurysm in such a locale, the preoperative measurement of arterial and aortic dimensional variables necessary to form a suitable endograft has proven to be complex. Any misfit in preparing a conventional stent graft to treat an aneurysm in this region results in lumenal obstruction or collapse, or material fatigue, resulting in continued blood flow into the aneurysm.
WO 03/082153, FIGS. 7-11, is representative of the stent grafts for the treatment of suprarenal aortic aneurysms. This graft includes a single lumen containing a Gianturco type zigzag Z stent tube in communication at a distal end with an aperture in the lumen and free floating at the proximal end within the lumen. Unfortunately, the free-floating tube proximal end is prone to damage during insertion of a sleeve therefrom into an artery in registry with the aperture, as well as under hemodynamic operating conditions.
Thus, there exists a need for a vascular endograft capable of treating an aneurysm in a vessel having adjacent vessel branches.